Gas tube circuits



Feb. 15, 1938. SWART 2,108,219

GAS TUBE CIRCUITS Filed July 3, 1936 INVENTOR C. j ATTORNEY Patented Feb. '15, 1938 UNITED STATES PATENT OFFICE GAS CIRCUITS Application July 3, 1936, Serial No. 88,905

6 Claim.

This invention relates to gas-filled tubes and to circuits for gas-filled tubes.

More particularly, this invention relates to circuits employing gas-filled tubes for the produc- 6 tion of oscillating or pulsating currents.

Still more particularly, this invention relates to circuits employing gas-filled tubes in which a source of potential such as a battery, and a condenser and resistor are connected to the electrodes of the tube or tubes for the purpose of producing tones or pulses for the timed'operation of an electrical or other device.

This invention will be better understood from. the detailed description hereinafter following when read in connection with the accompanying drawing in which Figural illustrates one embodimerit of the invention for producing tones; Fig. 2 is a modification in which only flashes are produced in the gas-filled tube of the circuit; Fig. 3 20 illustrates how a relay may be periodically operated by the circuit; Fig. t shows another modi-- flcation for the periodic operation of a relay; Fig. 5 illustrates a transformer arrangement through which are transmitted tones or electrical pulses; Fig. 6 shows two gas tubes arranged in tandem, the second tube of which may be connected to a load or electrical circuit; Fig. 7 illustrates a gas tube in tandem with a vacuum tube or hot cathode type of gas-filled tube; Fig. 8 shows an arrangement oi. a two-electrode gasfllled tube; Fig. 9 is a modification of Fig. 8 having an additional tube, the additional tube being of the three-electrode type; and Fig-d0 illustrates how the second tube may be a vacuum tube or a 35 hot cathode type of gas-filled tube.

In Fig. 1 of the drawing, the condenser C is connected to a battery B1 or other source of direct current potential through a resistor R1 and the anode A and cathode K1 of the tube N1. The

40 resistor R2 is connected across these same two electrodes A and K1 of the tube N1 through the battery B1. A pair of phones Por other indieating device-may be connected between the cathodes K1 and K2 of the tube Ni.

exceeding the breakdown voltage between electrodes A and K1 of the tube. This battery sends current through the resistor R: and over the path between the electrodes A and K1 of the tube, 50 thereby ionizing the gas within the tube. As current flows through resistor R: a. corresponding voltage will be established thereacross and this voltage will be applied to the condenser 0 through the resistor R1, the size of the latter resistor eontrolllng the charging rate of the condenser. As a The battery B1 may have a terminal voltage voltage becomes applied to the condenser C upon charge, this voltage will be transmitted;- to the electrodes A and K1 of the tube N1 in a direction which is the reverse of that produced by battery B1. In other words, the voltage of the condenser C will oppose and diminish the efiect of the voltage of battery B1 upon electrodes A and As the voltage across the condenser 6 reaches a value such that the voltage of batters E1 is greater in its efiect on electrodes is and P221 than that of the condenser C by an amount which is less than the sustaining volta'ge value of the gas between these electrodes of the tube, the gas will become'deionized. The gas will remain deionized until the voltage across electrodes A and K1 again reaches the breakdown voltage between these electrodes.

When the gas within" the tube Ni becomes dc ionized, the impedance between electrodes and K1 will become very high-in fact, so high that battery Bl will be unable to transmit current over resistor R2 and through the tube. The only volt age across resistor R2 will then be that produced by the discharge of condenser C which is in he direction opposing that of battery B1, as already pointed out.

When the condenser C has discharged to such an extent that the voltage eiiect of battery E1 on electrodes A and K1 exceeds that produced by the condenser C by an amount equal to the breakdown voltage value between these electrodes, the gas of the tube will be again ionized. The con= denser C will be recharged and when recharged to a sufliciently high voltage, the gas within the tube N1 will become deionized again, as already explained. This ionization and deionization of the gas within the tube will recur regularly and. Periodically at an interval (or intervals) deter mined by the constants of the elements of the circuit.

The phones P are connected between the catio odes K1 and K: of the tube Ni- When the gee of the tube is ionized, current will be transmitted. from the battery B1 through these'phones over the path which includes the resistor R2 and the anode A and catode K: of the tube. When the gas becomes deionized, the flow of current through phones P will cease.- Thustones will be heard in the phones P at regular and predetermined lntervals.

In Fig. 2, the two cathodes of tube N1 of Fig. l are connected together and are designated K. This tube N1 may be replaced by any gas-filled tube of the two-electrode type, it so desired. No

phones are connected in the arrangement of Fig. 2.

As in Fig. 1, the battery B1 supplies a voltage between electrodes A and K through to resistor R2 and this voltage will be suflicient to ionize the gas within the tube. The battery B1 also supplies current to charge the condenser C. During gaseous ionization, the tube will be illuminated.

After condenser C becomes charged to a sumcient voltage, it will reduce the voltage efiect of battery B1 below the sustaining value of the tube. When this occurs, the gas of the tube will become deionized and the luminous glow of the tube extinguished. Thus the tube N1 will flash at regular and predetermined intervals according to the ionization and deionization within the tube N1.

Fig. 3 is a modification of Fig. 2 in which the battery B1 is interposed between the upper terminal of resistor R2 and the anode A of tube N1 and, moreover, the winding of the relay W is conset-ween the lower terrni of the resis- Qty and the -iathode Is. of the wine.

V/hile the battery is impressing a voltage between the electrodes of the tube, which is so much greater than that of the voltage at discharge of the condenser C that the gas of the tube becomes ionized, current will flow from the battery through the relay winding and operate the relay. As the net voltage across the electrodes of the tube becomes reduced below the sustaining voltage of the tube, the gas of the tube will become deionized and the relay will be released. Hence the armature of the relay will follow the ionization and deionization of the gas of the tube.

Fig. l is a modification of the arrangement of 3 in which the winding of the relay W is connected in the circuit between cathodes K1 and E2 of the tube N1. Two separate batteries 31 and B2 are connected to the circuit, the battery 31 being employed for supplying positive voltage to the anode A of tube N1, the battery B2 being placed in series with the relay winding and the electrodes K1 and K2 of the tube. It will be understood that the two batteries B1 and. B2 may be but a single battery tapped in such way as to exhibit the eifect of the two individual batteries illustrated.

The battery B1 will initiate ionization of the gas Within the tube N1 by applying a sufliciently high voltage between the electrodes A and Ki of the tube and thereafter cause the condenser C to become charged to a progressively higher voltage. As the voltage charge of the condenser reaches a predetermined value, the voltage between the electrodes A and K1 will then become insuillcient to sustain ionization of the gas therebetween and the battery B1 will therefore cease to supply further'current to the circuit. During the interval when the gas of the tube is ionized, the battery B2 will supply current through the winding of the relay W and over the path of the electrodes K1 and K2 of the tube and the relay will operate. Upon deionization of the gas, the battery 13: will be of insuificient voltage to maintain the relay W operated and thereafter the latter relay will release. The two voltages derived from batteries B1 and B2 are insufiicient per se to maintain gaseous ionization within the tube after deionization has occurred.

Fig. 5 is a modification of Fig. 4 in which a transformer T replaces the relay W. The primary of the trarsformer will be energized according to the ionization of the gas within the tube. Current will flow through the secondary winding of the transformer only when the primary winding becomes energized and this current will cease immediately after delonization of the gas has occurred.

Fig. 6 is a modification of the arrangements of Figs. 4 and 5 in which two tubes N1 and N: are connected in tandem. The battery 13: is connected in series with the resistor R; and cathodes K1 and K: of the tube N1. The resistor R: and battery 13: are also connected across the electrodes K1 and K4 of the tube N2. Anode A: of the tube N: is connected in a load or other circuit which may be supplied with current from the battery B3 or other source.

In Fig. 6, the battery B1 will initiate ionization of the gas within tube N1 and at the same time cause the condenser C to become charged. Upon reaching a predetermined voltage at charge, the condenser C will so oppose and diminish the effect of the battery 31- as to reduce the voltage between electrodes of A and K1 below that required to sustain ionization of the gas therebetween.

During ionization of the gas within tube N1,

the battery B2 will supply current over the path of resistor R3 and the electrodes K1 and K: of the tube N1. The' voltage across resistor R3 and battery B2 will also ionize the gas between cathodes K3 and K4 of the tube N2 and the load circuit of anode A2 will become operated.

Duringthe interval when the gas of tube N1 is deionized, no current will flow through the resistor R3, the gas of tube N2 will become deionized and the load circuit connected to 'the anode A2 will not be operated.

As in Fig. 4, the batteries B1 and B: may be a single source of potential and tapped, if desired, so as to exhibit the eifect of two individual batteries or sources of potential. Moreover, a transformer of well-known type may replace the resistor R3, as will be readily understood. Such a transformer may, for instance, include two windings as in Fig. 5, one of which is in series with the battery B2 and the electrodes K1 and K: of the tube N1 and the other of which is connected across the electrodes K3 and K4 of the tube N: in series with the battery 13:. Furthermore, an audible or other signaling device may be connested in series with the anode A2 of the tube N: for the purpose of audibly indicating the periodic operation of the tube N1.

In Fig. 7, a hot cathode tube N: is substituted for the cold cathode, gas-filled tube N2 of Fig. 6. Tube N3 may be a vacuum tube or a gas-filled tube. The tube N3 may include a grid S, a plate or anode P, a cathode K5 and a heater H which is connected to one 01f the windings of the transformer T2, the other winding of which may be connected to a source of alternating current G.

In Fig. '7, the resistor R3 is connected between the grid S and the cathode K5 of the tube N3. The output or load circuit may be connected between the anode or plate P and the cathode K5 of the tube.

When ionization of the gas of the tube N1 takes place, the battery B: will send current through the resistor R3 over the path of cathodes K1 and m of tube N1. The potential across the resistor R: will result in ionization of the gas within tube N3. Thereafter, current will freely flow through the load or output circuit of the tube N3.

Fig. 8 is a modification of the arrangement shown in Fig. 2,.in which a two-electrode gasfilled tube N415 employed, the electrodes of which are connected in series with the battery Bi and the primary winding of transformer T, the latter series circuit being connected to the terminals of resistor R2. The secondary winding of the transformer T may be connected to a load or other circuit. The tube N4 will periodically flash as the voltage across its electrodes rises above the breakdown voltage of the tube and after lowered below the sustaining voltage of the tube. As in the case of Fig. 2, this flash will recur at regular and predetermined intervals. The load circuit may include a toneproduci'ng de: vice such as a pair of phones or any other" translating device (not shown).

In Fig. 9 the resistor R: replaces the transformer T of Fig. 8. The resistor R: is connected through the battery B2 to the cathodes K: and K4 oi the gas tube N2. The anode A: and the cathode K4 may be termed the output or load circuit of the tube N2.

In Fig. 9 the tubes N2 and N4 will flash almost simultaneously, at regular and predetermined intervals, according to the constants of the'clr-v cults. Thus the load circuit of the tube N: may be operated periodically, according to the ionization and deionization of the gas within tubes Na and N4.

Fig. 10 is a modification of the arrangement of Fig. 9, in which the tube N2 is replaced by the hot cathode type of tube .N's. The resistor R: is connected between the grid Sand the cathode Ks through a rectifier Y which permits the grid or input circuit of the tube N3 to be energized only by unidirectional current. A resistor R4 is also connected between grid S and cathode Ks as illustrated. The grid will be periodically polarized by the unidirectional current flowing through rectifier Y; The output or load circuit the tube N3 may be operated only when the grid 8 is properly polarized.

In all of the figures of the drawing, the operations are primarily governed by properly proportioning the condenser C, the resistances Rx and R2 and the value of the potential of the battery B1 or other direct current source. when these elements are correctly proportioned, the

gas tube N1, for instance, whether it be of they two-element or three-element type, may be made to automatically reset itself at regular intervals.

In all of the arrangements shown, a glow is produced in the tube N}. (or tube N4). This glow disappears periodically. If the resistor R1 is reduced to a practical nullity, the time of flash, as indicated by the illumination of the elements of the tube N1 (or tube N4), will be very short. The duration of the gaseous ionization or of this illumination may be controlled by increasing the value of the resistance R1 so that the discharge time across the elements of the tube may be longer drawn out. Moreover, by adjustment oi the,

resistance R2, the interval between pulses may be regulated for a given value of the condenser C.

In these arrangements, a small amount of apparatus is required for producing tones or pulses or for the operation at periodic intervals of oscillographs or other apparatus which may be connected in. the load or other circuits. Simple methods are thus available for the modulation of ringing currents, for example, or for the modulation of carrier frequencies at the rate at which ionization or deionization occurs within a gas tube. These arrangements may be employed for the regulation of the time at which signaling lights for the control of traillc may be operated or for operating other regulating devices or flash- .ployed where the presence of harmonics will not be objectionable. However, a filter (not shown) may be connected to the circuit as, for example,

across the secondary winding of transformer T of Figs. 5 and 8 or in the output or load circuits of any of the otherflgures such as 6, 7, 9 and 10. Such afllter will smooth out the wave form of the current generated by the system.

The battery B: may be poled in the direction indicated in the drawing. In other words, the battery i8: is preferably poled in the same direction as battery Bi so that both batteries will be in series with each other, the positive pole of battery B5 beingconnected to the negative pole oi battery B1. However, such a polarity is not essential to the operation of the apparatus and the apparatus will operate as effectively it the polarity of battery B2 is reversed, provided the battery B: does not produce too great a voltage.

While this invention has been shown and described in certain particular arrangements mere,

ly for the purpose of illustration, it will be undeparting from the spirit of the invention andthe scope of the appended claims.

What is claimed is:

l. The combination of a condenser, a resistor shunting the condenser, a three-electrode gasiilled tube, and a source of potential connected in series both with two of the electrodes of the tube and said resistor and having a potential which exceeds the breakdown voltage between said two electrodes of the tube, and an indicating device having a single pair of terminals connected between one of said two electrodes and the third electrode of said tube and responsive to the ion ization of the gas within the tube.

2. The combination of a gas-filled tube having a plurality of electrodes, a condenser, a source of direct voltage which exceeds the breakdown voltage of the tube and connected in series with two of the electrodes of said tube and'said condenser, means responsive to the application of voltage from said source ior producing ionization of the gas within the tube and then for charging the condenser to a progressively higher voltage, means responsive to the attainment of a predetermined voltage at charge across the condenser for deioniz'ing the gas within the tube, a resistor L between one of said two electrodes and a third electrode oi'said tube for indicating and responding to the ionization or deionization of the gas of said tube.

3. Automatic pulse-producing a paratus com-' prising parallel elements of resistance and capacitance, a gas tube of three electrodes, 9. source of potential connected in series with two of the electrodes of said tube and with said elements and having a voltage which exceeds the breakdown voltage of the'tubefsaid condenser being periodically charged by said source to a. predetermined voltage, said resistor forming a path to periodically discharge the condenser after the gas I within the tube has become deionized, and a pulse responsive indicating device connected between one of said two electrodes and the third electrode of said tube.

4. The combination of, a condenser, first and second resistors which are connected in series with each other and in series with said condenser, a three-electrode gas-filled tube, a source oi potential connected in series with two of the electrodes of the tube and said second resistor and having a potential which exceeds the breakdown voltage between said two electrodes of the tube, and an indicating device having a single pair of terminals connected between one of said two electrodes and the third electrode of said tube and responsive to the ionization of the gas within the tube.

5. The combination of a gas-filled tube having a plurality of electrodes, a condenser, a resistor, and a source of direct voltage which exceeds the breakdown voltage of the tube and connected in series both with said condenser and resistor and with two 0! the electrodes of said tube, means responsive to the application of voltage from said source for producing ionization of the gas within the tube and then for charging the condenser to a. progressively higher voltage, means responsive to the attainment oil a predetermined voltage at charge across the condenser for deionizing the gas within the tube, a second resistor through which the condenser discharges to reduce the voltage across the condenser alter the gas has become deionized, and a device connected between one of said two electrodes and a third electrode of said tube for indicating and responding to the ionization or deionization of the gas of said tube.

6. Automatic pulse-producing apparatus comprising flrst and second elements of resistance and an element of capacitance all connected in series with each other, a gas tube of three electrodes, a source of potential connected in series with two of the electrodes of said tube and with said first element 01' resistance and with said condenser, said source having a voltage which exceeds the breakdown voltage of the tube, said condenser being periodically charged by said source to a predetermined voltage, said second element of resistance forming a path to periodically discharge the condenser aiter the gas within the tube has become deionized, and a pulse-responsive indicating device connected between one of said two electrodes and the third electrode of said tube.

LELAND K. SWART. 

